The present invention relates to digital image forming equipment capable of selectively operable as a digital copier, facsimile transceiver and printer and, more particularly, to a sheet discharging device for such equipment which discharges a sheet carrying an optical image thereon to the outside of the equipment.
Complex image forming equipment having multiple functions as stated above is extensively used today. A digital copier, for example, is operable not only in a copier image input mode but also in a facsimile image input mode and a printer image input mode, as desired. This type of copier transmits or receives data to or from a remote station over a subscriber line or prints out data sent from a host computer on a sheet in a printer mode. The image formed in any one of such modes is transferred to and fixed on a sheet. The sheet carrying the image thereon is driven out of the copier to a tray or a sorter or similar finisher which is selectively mounted on the copier, the sorter having multiple bins therein. It follows that the sheets or copies produced by a particular mode have to be discharged in an optimal fashion matching the characteristics of the mode. For example, if the sheets undergone the different mode operations are driven out to a single tray, they will be mixed together and dealt with incorrectly in the finishing stage. Sheets carrying images produced in the printer mode or the facsimile mode are usually discharged face up from the first page to the last page and, therefore, have to be rearranged in order of page after the discharge. Hence, this kind of sheets should preferably be discharged face down, the first page being first. A sheet discharging device incorporated in a conventional image forming equipment operable only in a copier mode, i.e., an ordinary copier, has a function of turning over sheets undergone simple copier mode operations before driving them out from the copier, as needed. This kind of device, however, cannot implement an optimal discharge procedure matching a particular mode when applied to complex image forming equipment which is operable in various modes.